How long have you had your RX and is this your first time working with HID cars? I have to ask because for city driving, HID's are usually washed out by the street lights and may seem dim unlike halogen and LED which punch through better. But in the country, HID's excel.

At the same time, if you are on your original bulbs, they do get slightly dim over time but it's not significant like halogens. I usually recommend 4300K bulbs by Philips or Osram as that gives the maximum light output and is factory spec but unfortunately is white with a yellow hue to it. My next set will be Osram 6000K bulbs for an ice-white look which I'm willing to take the hit on light output for color as my RX really only gets city driving anyways.

 

I bought an 2010 LS 460L back in 2011, but I let the dealer do all the work on that car. My experience is more towards the halogen side because I used to own a 2003 ES 300 before I traded up to this RX. The big reason I would like to upgrade is because the HIDs in the LS are great for city/country road, however these RX HID's light output is terrible compared to my LS. I know that I cant really compare them, but I might just by the HID light replacement like you suggested. Also I have owned this 131000 mile RX for two months, and I don't have any previous service records from the previous owner.

 

A bulb upgrade will probably help especially if you change the kelvin to something cooler like 5000-6000K which punches deeper at the cost of overall brightness. Also you are right, the LS is incomparable, I have driven a 2006 LS430 and also know what is used for the HID components and our RX comes nowhere near. Too bad the projectors wouldn't fit in my Camry's housing without significant mods otherwise I would have used the LS over the MDX.

 

Yea I might have to do that... but I think my HIDs are just aged. I might need to call lexus dealer and see if they might give me a complete history of the services performed by the previous owner. For HIDs they should not be this dim in in my RX.